Independently Actuated Wheel Sets for Large Autonomous Self-Driving Vehicles

ABSTRACT

The technology relates to fine maneuver control of large autonomous vehicles that employ multiple sets of independently actuated wheels. The control is able to optimize the turning radius, effectively negotiate curves, turns, and clear static objects of varying heights. Each wheel or wheel set is configured to adjust individually via control of an on-board computer system. Received sensor data and a physical model of the vehicle can be used for route planning and selecting maneuver operations in accordance with the additional degrees of freedom provided by the independently actuated wheels. This can include making turns, moving into or out of parking spaces, driving along narrow or congested roads, construction zones, loading docks, etc. A given maneuver may include maintaining a minimum threshold distance from a neighboring vehicle or other object.

CROSS-REFERENCE TO RELATED APPLICATIONS

This present application is a continuation of U.S. patent applicationSer. No. 16/863,450 filed Apr. 30, 2020, which claims the benefit of thefiling date of U.S. Provisional Application No. 62/901,859, filed Sep.18, 2019, the entire disclosures of which are incorporated herein byreference.

BACKGROUND

Autonomous vehicles, such as vehicles that do not require a humandriver, can be used to aid in the transport of cargo or passengers fromone location to another. Such vehicles may operate in a fully autonomousmode, or a partially autonomous mode where a person may provide somedriving input. Large self-driving vehicles such as tractor-trailertrucks and other cargo vehicles, articulating buses, fire trucks and thelike include multiple sets of wheels. Typically, only the front wheelset (e.g., of the truck's tractor) are able to turn. This gives suchvehicles a large turning radius, which makes it challenging to maneuverinto and out of tight locations, such as a loading dock or narrowstreet. Sensors may be used to help the autonomous vehicle detect nearbyobjects while driving. However, self-driving operations may be limitedby the ability to turn in a desired direction given the vehicle'sturning radius.

BRIEF SUMMARY

The technology relates to large autonomous vehicles that employ multiplesets of independently actuated wheels to optimize the turning radius,effectively negotiate curves, turns, clear objects of varying heights(e.g., curbs) and generally maneuver well in tight spaces. Each wheel orwheel set may turn a different amount under control of an on-boardcomputer system. The on-board computer system employs received sensordata to detect objects and situations in the environment around thevehicle. A physical model of the self-driving vehicle, including height,length, width, pivot point and turning radius, can be used inconjunction with the sensor data for route planning and drivingoperations in accordance with the physical characteristics of thevehicle including the additional degrees of freedom provided by theindependently actuated wheels.

According to one aspect of the technology, a vehicle is configured tooperate in an autonomous driving mode. The vehicle has a driving systemincluding a steering subsystem, an acceleration subsystem and adeceleration subsystem to control driving of the vehicle in theautonomous driving mode. It also has a plurality of wheels arranged intwo or more wheel sets, where each wheel set is configured forindependent actuation by the driving system relative to the other wheelsets. A perception system of the vehicle includes one or more sensorsconfigured to detect objects in an environment surrounding the vehiclebased on obtained sensor data, where each of the one or more sensors ispositioned along the vehicle. The vehicle also includes a control systemoperatively connected to the driving system and the perception system.The control system has one or more computer processors configured toreceive sensor data from the perception system, create a control planbased on the received sensor data, identify selected ones of theplurality of wheels in the two or more wheel sets to adjust based on thecontrol plan, and actuate the identified wheels independently of oneanother according to the control plan when operating in the autonomousdriving mode.

In one example, the vehicle is a cargo vehicle having a tractor and atleast one trailer pivotally coupled to the tractor. In this case, thecontrol plan includes changing a position or orientation of the at leastone trailer unit relative to the tractor.

In another example, the control system is configured to cause theselected wheels in the two or more wheel sets to vary position to causea lateral movement of the vehicle. Here, the control system may beconfigured to cause the selected wheels in the two or more wheel sets tovary position to provide braking or to avoid jackknifing of the vehicle.

In a further example, the control system is configured to cause theselected wheels in the two or more wheel sets to vary position to altera pivoting axis the vehicle. In yet another example, the control systemis configured to cause the selected wheels in the two or more wheel setsto vary position to reduce a blind spot of the perception system.

The control plan may include a maneuver selected from the groupconsisting of a parking maneuver, a turning maneuver, and a backing upmaneuver.

In another example, the control system stores a model of the vehicle. Inthis case, the control system may be further configured to create thecontrol plan based on the vehicle model. The control plan may be createdto minimize a swept volume of the vehicle along a route in accordancewith the vehicle model. Alternatively or in addition, the control planmay include adjusting a height of a portion of the vehicle to avoid anobject detected by the perception system. The control plan may also becreated to maintain a threshold distance from another vehicle in theenvironment.

According to another aspect, a method of controlling a vehicleconfigured to operate in an autonomous driving mode is provided. Thevehicle includes a plurality of wheels arranged in two or more wheelsets, where each wheel set is configured for independent actuationrelative to the other wheel sets. The method comprises receiving, by oneor more processors of a control system of the vehicle, sensor data froma perception system of the vehicle; creating, by the one or moreprocessors, a control plan based on the received sensor data;identifying, by the one or more processors, selected ones of theplurality of wheels in the two or more wheel sets to adjust based on thecontrol plan; and actuating the identified wheels independently of oneanother according to the control plan when operating in the autonomousdriving mode.

In one example, the vehicle is a cargo vehicle having a tractor and atleast one trailer pivotally coupled to the tractor, and the control planincludes changing a position or orientation of the at least one trailerunit relative to the tractor.

In another example, actuating the identified wheels according to thecontrol plan is to either alter a pivoting axis the vehicle, or reduce ablind spot of the perception system.

In a further example, the control plan includes a maneuver selected fromthe group consisting of a parking maneuver, a turning maneuver, and abacking up maneuver.

In yet another example, the control plan includes adjusting a height ofa portion of the vehicle to avoid an object detected by the perceptionsystem. The control plan may be created to minimize a swept volume ofthe vehicle along a route in accordance with a stored vehicle model.Alternatively or in addition, the control plan may be created tomaintain a threshold distance from another vehicle in an environmentsurrounding the vehicle.

And according to another aspect, a non-transitory computer-readablerecording medium is provided with stored instructions. The instructions,when executed by one or more processors of a computer, cause the one ormore processors to perform a method of controlling a vehicle configuredto operate in an autonomous driving mode. The vehicle includes aplurality of wheels arranged in two or more wheel sets, where each wheelset is configured for independent actuation relative to the other wheelsets. The method comprises receiving sensor data from a perceptionsystem of the vehicle; creating a control plan based on the receivedsensor data; identifying selected ones of the plurality of wheels in thetwo or more wheel sets to adjust based on the control plan; andactuating the identified wheels independently of one another accordingto the control plan when operating in the autonomous driving mode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-B illustrate an example cargo-type vehicle configured for usewith aspects of the technology.

FIGS. 2A-B are block diagrams of systems of an example cargo-typevehicle in accordance with aspects of the technology.

FIG. 3 illustrates example sensor fields of view for a cargo-typevehicle in accordance with aspects of the disclosure.

FIG. 4 illustrates an example sensor scan operation in accordance withaspects of the technology.

FIG. 5 illustrates examples of object height variation in accordancewith aspects of the technology.

FIGS. 6A-B illustrate an example scenario for reducing the risk ofjackknifing in accordance with aspects of the technology.

FIGS. 7A-D illustrate a parked scenario in accordance with aspects ofthe technology.

FIGS. 8A-C illustrate a turning scenario in accordance with aspects ofthe technology.

FIGS. 9A-G illustrate a backing-up scenario in accordance with aspectsof the technology.

FIG. 10 illustrates a view showing examples where the vehicle ispivotable about different points.

FIGS. 11A-B illustrates an example system in accordance with aspects ofthe technology.

FIG. 12 illustrates an example method in accordance with aspects of thetechnology.

DETAILED DESCRIPTION

Features of the technology involve maneuvering a large self-drivingvehicle by adjusting multiple wheels or wheel sets independently of oneanother, for instance to achieve a minimum turning radius or otherwisemodify driving operations to avoid nearby objects. This can includemaking turns, moving into or out of parking spaces, driving along narrowor congested roads, etc. The vehicle's on-board computer system can takereal-time corrective action or modify a planned route in accordance withthe capabilities afforded by the independently actuated wheels. Thetechnology is beneficial in different types of environments. Forinstance, fine wheel control can allow the on-board control system toplan an efficient route or specific maneuvers in residentialneighborhoods, construction zones, loading docks, etc.

Example Vehicle Systems

FIGS. 1A-B illustrate an example cargo vehicle 100, such as atractor-trailer truck. FIG. 1A is a side view and FIG. 1B is a top-downview. The truck may include, e.g., a single, double or triple trailer,or may be another medium or heavy duty truck such as in commercialweight classes 4 through 8. As shown, the truck includes a tractor unit102 and a single cargo unit or trailer 104. The trailer 104 may be fullyenclosed, open such as a flat bed, or partially open depending on thetype of cargo to be transported. In this example, the tractor unit 102includes the engine and steering systems (not shown) and a cab 106 for adriver and any passengers. In a fully autonomous arrangement, the cab106 may not be equipped with seats or manual driving components, sinceno person may be necessary.

The trailer 104 includes a hitching point, known as a kingpin, 108. Thekingpin 108 is typically formed as a solid steel shaft, which isconfigured to pivotally attach to the tractor unit 102. In particular,the kingpin 108 attaches to a trailer coupling 110, known as afifth-wheel, that is mounted rearward of the cab 106. For a double ortriple tractor-trailer, the second and/or third trailers may have simplehitch connections to the leading trailer. Or, alternatively, eachtrailer may have its own kingpin. In this case, at least the first andsecond trailers could include a fifth-wheel type structure arranged tocouple to the next trailer.

As shown, the tractor and/or trailer may have one or more sensor units112, 114 and 116 disposed therealong. For instance, one or more sensorunits 112 may be disposed on a roof or top portion of the cab 106, andone or more side sensor units 114 may be disposed, e.g., on left and/orright sides of the cab 106. In some cases, such sensor units may belocated on the top of, on the bottom of, adjacent to, or in place ofrear-view mirrors. Sensor units may also be located along other regionsof the cab 106, such as along the front bumper or hood area, in the rearof the cab adjacent to the fifth-wheel, underneath the chassis, etc. Thetrailer 104 may also have one or more sensor units 116 disposedtherealong, for instance along a side panel, front, rear, roof and/orundercarriage of the trailer 104.

By way of example, each sensor unit may include one or more sensors,such as lidar, radar, camera (e.g., optical or infrared), acoustical(e.g., microphone or sonar-type sensor), pressure (e.g., piezoelectricor mechanical), inertial (e.g., accelerometer, gyroscope, etc.) or othersensors (e.g., positioning sensors such as GPS sensors). Acousticalsensors near the tires (e.g., on the vehicle chassis near the axles orwheel wells) can detect the sounds of the tires as the vehicle drivesautonomously along the roadway. A change in sound may indicate adifferent road surface type, a flat or underpressurized tire or othercircumstance. Pressure sensors could be used to detect instantaneoustire pressure or the weight distribution of cargo. While certain aspectsof the disclosure may be particularly useful in connection with specifictypes of vehicles, the vehicle may be any type of vehicle including, butnot limited to, trucks and other cargo vehicles, buses, cars,motorcycles, recreational vehicles, etc.

There are different degrees of autonomy that may occur for a vehicleoperating in a partially or fully autonomous driving mode. The U.S.National Highway Traffic Safety Administration and the Society ofAutomotive Engineers have identified different levels to indicate howmuch, or how little, the vehicle controls the driving. For instance,Level 0 has no automation and the driver makes all driving-relateddecisions. The lowest semi-autonomous mode, Level 1, includes some driveassistance such as cruise control. Level 2 has partial automation ofcertain driving operations, while Level 3 involves conditionalautomation that can enable a person in the driver's seat to take controlas warranted. In contrast, Level 4 is a high automation level where thevehicle is able to drive without assistance in select conditions. AndLevel 5 is a fully autonomous mode in which the vehicle is able to drivewithout assistance in all situations. The architectures, components,systems and methods described herein can function in any of the semi orfully-autonomous modes, e.g., Levels 1-5, which are referred to hereinas autonomous driving modes. Thus, reference to an autonomous drivingmode can include both partial and full autonomy.

FIG. 2A illustrates a block diagram 200 with various components andsystems of an exemplary vehicle, such as cargo vehicle 100, to operatein an autonomous driving mode. As shown, the block diagram 200 includesa control system having one or more computing devices 202. The controlsystem may constitute an electronic control unit (ECU) of a tractor unitof the cargo vehicle 100. The computing devices 202 contain one or moreprocessors 204, memory 206 and other components typically present ingeneral purpose computing devices. The memory 206 stores informationaccessible by the one or more processors 204, including instructions 208and data 210 that may be executed or otherwise used by the processor(s)204. For instance, the data 210 may include a model of the vehicle, suchas a kinematic model for both the tractor and trailer(s). The computingsystem is able to control overall operation of the vehicle whenoperating in an autonomous driving mode according to the vehicle model.

The memory 206 stores information accessible by the processors 204,including instructions 208 and data 210 that may be executed orotherwise used by the processors 204. The memory 206 may be of any typecapable of storing information accessible by the processor, including acomputing device-readable medium. The memory is a non-transitory mediumsuch as a hard-drive, memory card, optical disk, solid-state, etc.Systems may include different combinations of the foregoing, wherebydifferent portions of the instructions and data are stored on differenttypes of media.

The instructions 208 may be any set of instructions to be executeddirectly (such as machine code) or indirectly (such as scripts) by theprocessor. For example, the instructions may be stored as computingdevice code on the computing device-readable medium. In that regard, theterms “instructions”, “modules” and “programs” may be usedinterchangeably herein. The instructions may be stored in object codeformat for direct processing by the processor, or in any other computingdevice language including scripts or collections of independent sourcecode modules that are interpreted on demand or compiled in advance. Thedata 210 may be retrieved, stored or modified by one or more processors204 in accordance with the instructions 208. In one example, some or allof the memory 206 may be an event data recorder or other secure datastorage system configured to store vehicle diagnostics, detected sensordata, per-vehicle calibration parameters and/or per-trailer calibrationparameters, which may be on board the vehicle or remote, depending onthe implementation.

The processors 204 may be commercially available CPUs. Alternatively,each processor may be a dedicated device such as an ASIC or otherhardware-based processor. Although FIG. 2A functionally illustrates theprocessors, memory, and other elements of computing devices 202 as beingwithin the same block, such devices may actually include multipleprocessors, computing devices, or memories that may or may not be storedwithin the same physical housing. Similarly, the memory 206 may be ahard drive or other storage media located in a housing different fromthat of the processor(s) 204. Accordingly, references to a processor orcomputing device will be understood to include references to acollection of processors or computing devices or memories that may ormay not operate in parallel.

In one example, the computing devices 202 may form an autonomous drivingcomputing system incorporated into vehicle 100. The autonomous drivingcomputing system may capable of communicating with various components ofthe vehicle. For example, the computing devices 202 may be incommunication with various systems of the vehicle, such as a drivingsystem including a deceleration system 212 (for controlling braking ofthe vehicle), acceleration system 214 (for controlling acceleration ofthe vehicle), steering system 216 (for controlling the orientation ofthe wheels or wheel sets and the direction of the vehicle), signalingsystem 218 (for controlling turn signals), navigation system 220 (fornavigating the vehicle to a location or around objects) and apositioning system 222 (for determining the position of the vehicle,e.g., including the vehicle's pose). The autonomous driving computingsystem may employ a planner module 223, in accordance with thenavigation system 220, the positioning system 222 and/or othercomponents of the system, e.g., for determining a route from a startingpoint to a destination, for selecting an intermediate section of theroute, or for making modifications to various driving aspects in view ofcurrent or expected conditions or situations along the route in view ofthe maneuvering capabilities of the vehicle.

The computing devices 202 are also operatively coupled to a perceptionsystem 224 (for detecting objects in the vehicle's environment), a powersystem 226 (for example, a battery and/or gas or diesel powered engine)and a transmission system 230 in order to control the movement, speed,etc., of the vehicle in accordance with the instructions 208 of memory206 in an autonomous driving mode which does not require or needcontinuous or periodic input from a passenger of the vehicle. Some orall of the wheels/tires 228 are coupled to the transmission system 230.Each wheel or wheel set may be separately adjustable. This may includecontrol over the turning angle, toe angle, camber angle, relativeheight, etc. of the given wheel(s). The computing devices 202 may beable to receive information about tire pressure, balance and otherfactors that may impact driving in an autonomous mode.

The computing devices 202 may control the direction and speed of thevehicle, e.g., via the planner module 223, by controlling variouscomponents. By way of example, computing devices 202 may navigate thevehicle to a destination location completely autonomously using datafrom map information and the navigation system 220. Computing devices202 may use the positioning system 222 to determine the vehicle'slocation and the perception system 224 to detect and respond to objectswhen needed to reach the location safely. In order to do so, computingdevices 202 may cause the vehicle to accelerate (e.g., by increasingfuel or other energy provided to the engine by acceleration system 214),decelerate (e.g., by decreasing the fuel supplied to the engine,changing gears, and/or by applying brakes by deceleration system 212),change direction (e.g., by turning the front or other wheels of vehicle100 by steering system 216), and signal such changes (e.g., by lightingturn signals of signaling system 218). Thus, the acceleration system 214and deceleration system 212 may be a part of a drivetrain or other typeof transmission system 230 that includes various components between anengine of the vehicle and the individual wheels or wheel sets of thevehicle. Again, by controlling these systems, computing devices 202 mayalso control the transmission system 230 of the vehicle in order tomaneuver the vehicle autonomously.

Navigation system 220 may be used by computing devices 202 in order todetermine and follow a route to a location. In this regard, thenavigation system 220 and/or memory 206 may store map information, e.g.,highly detailed maps that computing devices 202 can use to navigate orcontrol the vehicle. As an example, these maps may identify the shapeand elevation of roadways, lane markers, intersections, crosswalks,speed limits, traffic signal lights, buildings, signs, real time trafficinformation, vegetation, or other such objects and information. The lanemarkers may include features such as solid or broken double or singlelane lines, solid or broken lane lines, reflectors, etc. A given lanemay be associated with left and/or right lane lines or other lanemarkers that define the boundary of the lane. Thus, most lanes may bebounded by a left edge of one lane line and a right edge of another laneline.

The perception system 224 includes one or more sensor assemblies 232 fordetecting objects external to the vehicle. The detected objects may beother vehicles, obstacles in the roadway, traffic signals, signs, trees,etc. By way of example only, the sensor assemblies 232 of the perceptionsystem 224 may each include one or more light detection and ranging(lidar) sensors, radar units, cameras (e.g., optical imaging devices,with or without a neutral-density filter (ND) filter), positioningsensors (e.g., gyroscopes, accelerometers and/or other inertialcomponents), infrared sensors, acoustical sensors (e.g., microphones orsonar transducers), and/or any other detection devices that record datawhich may be processed by computing devices 202. Such sensors of theperception system 224 may detect objects outside of the vehicle andtheir characteristics such as location, orientation, size, shape, type(for instance, vehicle, pedestrian, bicyclist, etc.), heading, speed ofmovement relative to the vehicle, etc. In addition, the sensors maydetect road conditions, like standing water, ice, or potholes, as wellas the positions and orientations (pose) of different parts of thevehicle.

The perception system 224 may also include other sensors within thevehicle to detect objects and conditions within the vehicle, such as inthe trailer or passenger compartment. For instance, such sensors maydetect, e.g., cargo, passengers, pets, etc., as well as conditionswithin the vehicle or a component thereof, and/or outside the vehiclesuch as temperature, humidity, etc. Still further, sensors of theperception system 224 may measure the rate of rotation of the wheels228, an amount or a type of braking by the deceleration system 312,pressure, alignment and other factors associated with the equipment ofthe vehicle itself. Depending on the vehicle configuration, thelongitudinal position of the kingpin of the tractor may be adjustable.One or more sensors may be arranged to detect the specific longitudinalposition of the kingpin.

The raw data from the sensors and the aforementioned characteristics canbe processed by the perception system 224 and/or sent for furtherprocessing to the computing devices 202 periodically or continuously asthe data is generated by the perception system 224. Computing devices202 may use the positioning system 222 to determine the vehicle'slocation and perception system 224 to detect and respond to objects whenneeded to reach the location safely, e.g., via adjustments made byplanner module 223. In addition, the computing devices 202 may performcalibration of individual sensors, all sensors in a particular sensorassembly, or between sensors in different sensor assemblies or otherphysical housings.

As noted above, one or more sensors of the perception system 224 may beincorporated into sensor assemblies or housings. In one example, thesemay be integrated into the side-view mirrors on the vehicle, e.g., assensor towers integrated into the side-view mirrors on the truck, farmequipment, construction equipment or the like. In another example, othersensors may be part of the roof-top housing 112, or other sensorhousings or units 114 and/or 116. The computing devices 202 maycommunicate with the sensor assemblies located on or otherwisedistributed along the vehicle. Sensor assemblies 232 may also bepositioned at different locations on the tractor unit 102 or on thetrailer 104, as noted above with regard to FIGS. 1A-B. The computingdevices 202 may communicate with the sensor assemblies located on boththe tractor unit 102 and the trailer 104. Each assembly may have one ormore types of sensors such as those described above.

Also shown in FIG. 2A is a coupling system 234 for connectivity betweenthe tractor unit and the trailer. The coupling system 234 may includeone or more power and/or pneumatic connections 236 and a fifth-wheel 238at the tractor unit for connection to the kingpin of the trailer.

A communication system 240 is also shown as part of vehicle system 200.For instance, the communication system 240 may also include one or morewireless configurations to facilitate communication with other computingdevices, such as passenger computing devices within the vehicle,computing devices external to the vehicle such as in another nearbyvehicle on the roadway, and/or a remote server system. Such connectionsmay include short range communication protocols such as Bluetooth™,Bluetooth™ low energy (LE), cellular connections, as well as variousconfigurations and protocols including the Internet, World Wide Web,intranets, virtual private networks, wide area networks, local networks,private networks using communication protocols proprietary to one ormore companies, Ethernet, WiFi and HTTP, and various combinations of theforegoing.

FIG. 2B illustrates an example block diagram 250 of trailer-basedsubsystems, such as might be included in trailer 104 of FIGS. 1A-B. Asshown, the system includes an ECU 252 of one or more computing devices,such as computing devices containing one or more processors 254, memory256 and other components typically present in general purpose computingdevices. The memory 256 stores information accessible by the one or moreprocessors 254, including instructions 258 and data 260 that may beexecuted or otherwise used by the processor(s) 254. The descriptions ofthe processors, memory, instructions and data from FIG. 2A apply tothese elements of FIG. 2B.

The ECU 252 is configured to receive information and control signalsfrom the trailer unit. The on-board processors 254 of the ECU 252 maycommunicate with various systems of the trailer, including a wheelsteering system 261, a deceleration system 262, signaling system 264,and a positioning system 266. The ECU 252 may also be operativelycoupled to a perception system 268 with one or more sensors fordetecting objects in the trailer's environment and a power system 270(for example, a battery power supply) to provide power to localcomponents. Some or all of the wheels/tires 272 of the trailer may beindependently coupled to the wheel steering system 261 and thedeceleration system 262. The processors 254 may be able to receiveinformation about tire pressure, balance, temperature, wheel speed andother factors that may impact driving in an autonomous mode, and torelay that information to the processing system of the tractor unit. Thesteering system 261, deceleration system 262, signaling system 264,positioning system 266, perception system 268, power system 270 andwheels/tires 272 may operate in a manner such as described above withregard to the subsystems of FIG. 2A.

The trailer also includes a set of landing gear 274 as well as acoupling system 276. The landing gear provide a support structure forthe trailer when decoupled from the tractor unit. The coupling system276, which may be a part of coupling system 234, provides connectivitybetween the trailer and the tractor unit. Thus, the coupling system 276may include a connection section 278 (e.g., for power and/or pneumaticlinks). As shown, the coupling system 276 also includes a kingpin 280configured for connectivity with the fifth-wheel of the tractor unit.

Example Implementations

In view of the structures and configurations described above andillustrated in the figures, various aspects will now be described inaccordance with aspects of the technology.

As noted above, various sensors may be located at different placesaround the vehicle (see FIGS. 1A-B) to gather data from different partsof the external environment and/or the vehicle itself. Certain sensorsmay have different fields of view (FOV) of the external environmentand/or parts of the vehicle depending on their placement around thevehicle and the type of information they are designed to gather. Forinstance, different lidar sensors may be used for near (short range)detection of objects adjacent to the vehicle (e.g., less than 2-10meters), while others may be used for far (long range) detection ofobjects a hundred meters (or more or less) in front of the vehicle.Mid-range lidars may also be employed. Multiple radar units may bepositioned toward the front or rear of the vehicle for long-range objectdetection. And cameras may be arranged to provide good visibility aroundthe vehicle. Depending on the configuration, certain types of sensorsmay include multiple individual sensors with overlapping fields of view.Alternatively or additionally, other sensors may provide redundant 360°fields of view. In addition to detecting objects in the environmentexternal to the vehicle, these sensors may be used to determine thevehicle's actual pose including, e.g., the orientation of the trailer tothe tractor unit of a cargo vehicle.

FIG. 3 provides one example 300 of sensor fields of view relating to thesensors, such as those illustrated in FIG. 1B. As illustrated in example300 of FIG. 3 , the lidar(s) in the rooftop sensor housing 302 may havea FOV 304. Here, as shown by region 306, the trailer or otherarticulating portion of the vehicle may provide signal returns, and maypartially or fully block a rearward view of the external environment.Long range lidars of left and right side sensor units 308 a, 308 b ofthe tractor unit have FOVs 310 a and 310 b. These can encompasssignificant areas along the sides and front of the vehicle. As shown,there may be an overlap region 312 of their fields of view in front ofthe vehicle. The overlap region 312 provides the perception system withadditional or information about a very important region that is directlyin front of the tractor unit. This redundancy also has a safety aspect.Should one of the long range lidar sensors suffer degradation inperformance, the redundancy would still allow for operation in anautonomous mode. Short range lidars of the sensor units 308 a and 308 bhave smaller FOVs 314 a and 314 b. Both the long range and short rangelidars may be co-located in a single housing 308 a or 308 b as shown, ormay be disposed separately on the vehicle. A space is shown betweendifferent fields of view for clarity in the drawing; however, inactuality there may be no break in the coverage. The specific placementsof the sensor assemblies and fields of view is merely exemplary, and maydiffer depending on, e.g., the type of vehicle, the size of the vehicle,FOV requirements, etc.

These and other sensors are able to detect not only the location ofobjects in the environment, but also their height and other informationas well. This may be done by making multiple scans of the environment byone or more sensors. By way of example, FIG. 4 illustrates a vehicleusing sensor assembly to scan for objects in the environment. The sensorassembly may be, e.g., rooftop sensor housing 302 of FIG. 3 . The sensorassembly may include one or more lidar, radar, camera or other sensorstherein. Solid and dashed lines emanating from the housing indicateexamples of individual scans of the environment. For instance, 10 (ormore or less) individual scans may be made by a given sensor per scanperiod. This may include adjusting the sensor's FOV up or down, left orright, e.g., with a motor, servo or other actuator. The individual scansmay be selected to cover particular portions of the sensor's FOV orselected regions around the vehicle.

Based on this information, as shown by example 500 of FIG. 5 , theon-board control system may detect objects of different size, shape andheight, such as a passenger vehicle 502, bicycle 504, streetlight 506and street sign 508, no-parking sign 510, business signage (e.g., barberpole) 512, construction signage 514, mailbox 516, curb 518, etc. Theinformation about the locations and different heights of such objectscan be used in accordance with the vehicle model to plan how to orientthe wheel sets in order to achieve a particular driving operation orother maneuver. For instance, the trailer may have clearance over thecurb 518 to make a tight turn around a corner; however, sign 510 orstreetlight 506 may be located so that some maneuvers would cause theside or roof of the trailer to intersect with those object. Thus, adifferent maneuver may be planned to avoid such obstacles.

Example Scenarios

As noted above, aspects of the technology involve independentlyactuating different sets of wheels on the vehicle in order to enhanceits maneuverability. Information about such actuation capabilities and amodel of the vehicle may also be employed when modifying or re-plan anupcoming portion of a route to a given destination. For instance, theperception system of the tractor unit and/or trailer can be used todetect both objects in the environment as well as the vehicle's actualpose at the particular point in time along the region of the roadway.The vehicle's control system may use this information in accordance withthe vehicle model to actuate various wheels or wheel sets in specificorientations or patterns to perform specific maneuvers. Examples ofmaneuvers in specific scenarios are discussed below.

FIGS. 6A-B illustrate a jackknifing-avoidance scenario. As shown in 600of FIG. 6A, the truck may make a sharp turn, for instance to avoid anobject on the freeway or a surface street. If only the front wheels ofthe tractor are able to turn, a sharp turn can cause the truck tojackknife. However, as shown in 610 of FIG. 6B, different wheel sets maybe independently angled to cause the tractor and trailer to straightenout relative to one another. For instance, wheels of the tractor and thetrailer may be angled, for instance by turning in the same direction bythe same or different amounts.

FIGS. 7A-D illustrate a scenario involving maneuvering out of a tightspace, such as with on-street parking in a city environment. As shown inview 700 of FIG. 7A, a large vehicle such as a tractor-trailer is parkedwith vehicles both in front and behind. As shown in view 710 of FIG. 7B,which presents a partial see-through view of the trailer, some or all ofthe trailer and tractor wheel sets may be adjusted, e.g., via control ofthe steering and transmission subsystems. Depending on the vehiclecapabilities, in one example rotation of the wheels enables the vehicleto pull out of the parking spot. In another example, multiple wheel setsmay be pivoted, such as in a toe-in, toe-out pattern, to “walk” thevehicle laterally out of the parking spot. View 730 of FIG. 7Cillustrates the vehicle pulling out of the parking spot, and once thevehicle has pulled out, view 740 of FIG. 7D illustrates the vehicledriving away.

FIGS. 8A-C illustrate a scenario that uses rear steering to avoid acollision with another vehicle during a turn. As shown in view 800 ofFIG. 8A, a large vehicle is in one lane and another vehicle is in theadjacent lane. View 810 of FIG. 8B illustrates both vehicles beginning aturn (here a left turn). In a conventional situation, a large vehiclesuch as a tractor-trailer may need to turn sharply; however, this couldbring the vehicle too close to the other vehicle in the adjacent lane.Here, as shown in view 810, the wheel sets of the trailer and the rearwheels of the tractor are actuated to provide a tight turning radiuswhile leaving a sufficient distance from the neighboring vehicle. By wayof example, the on-board planner system may determine how much to angleeach wheel set in order to make the turn while staying in the same laneand maintaining a minimum (threshold) distance from the other vehicle.View 820 of FIG. 8C illustrates both vehicles as they complete theirturns. As shown here, the rear wheels of the tractor have straightenedout while the rear wheels of the trailer are still angled.

FIGS. 9A-9G present another scenario, in which the rear wheel sets areused to control the rear of a large vehicle while reversing. View 900 ofFIG. 9A illustrates a tractor-trailer prior to reversing. View 910 ofFIG. 9B shows the rear wheel sets of the trailer adjusted in preparationfor reversing. Here, the rear wheel sets may be angled the same ordifferent amounts, and each side may be adjusted differently. View 920of FIG. 9C shows the truck backing up, with the trailer angled inresponse to adjustment of the rear wheels. View 930 of FIG. 9D shows thetruck continuing backing up, here with some or all of the rear wheelssubstantially or completely parallel with the direction of movement. Asshown in view 940 of 9E, the trailer may be perpendicular to thecab/tractor after backing up. Then as shown in view 950 of FIG. 9F, oneor more sets of the tractor's wheels are used to adjust the orientationof the tractor while the trailer's wheels are not adjusted. And view 960of FIG. 9G illustrates the tractor in line with the trailer uponcompletion of the maneuver.

These and other large vehicle adjustment scenarios are performed byenabling individual wheels or wheel sets to move independently of otherwheels or wheel sets. This may be done via control over the turningangle, toe angle, camber angle, etc. of each wheel or wheel set. Suchrefined control allows the system to optimize the turning radius, andeffectively negotiate curves, turns, clear objects of varying heights(e.g., curbs) and generally maneuver well in tight spaces. FIG. 10illustrates a view 1000 showing several examples where the vehicle couldpivot about different points, such as about the kingpin, about the rearwheels, or about the center of the trailer. Nonetheless, via selectsadjustment of the wheels, a pivot point could be selected along anyregion of the vehicle.

The height of one or more portions of the vehicle may also beadjustable, for instance using hydraulic adjustment along the respectiveaxle components. Height adjustment may be performed by the planner inaccordance with the vehicle model and the received sensor data. Suchadjustment could reduce the amount of pitch experienced by the cargo,reduce or increase the height of the trailer to avoid nearby object, orsmooth out bumps during a turning or other driving maneuver.

The ability to control specific wheels gives the on-board computersystem an additional degree of freedom per additional steerable axle setthat can be used when maneuvering. Different trajectories can beplanned, for instance depending on different volumes of space that wouldbe swept by the trailer or other portion(s) of the vehicle. In oneexample, the wheels may be actuated to sweep the narrowest amount ofvolume, or the volume that avoids curbs or other objects, or avoidsjackknifing. In addition, the system may actuate the wheels to adjustthe vehicle's axis of rotation or to perform lateral moves.

As noted above, on-board sensors are employed to gather informationabout the external environment around the vehicle, and can be used toobtain pose and other information about the vehicle itself, such as anaccurate trailer position relative to the tractor. Independent wheelactuation may be employed for fine control of the vehicle's positioning,when may reduce blind spots around the vehicle. The on-board controlsystem is able to use the received sensor information and the vehiclemodel in conjunction with geographic data (e.g., maps) to plan routes orselect trajectories that are optimized for vehicle maneuvering. This mayinclude computing an ideal optimized trajectory for the trailer(s) basedon a given scenario.

One factor involved in such analysis includes keeping lateral buffers toother nearby vehicles in turns. The buffer(s) may be selected based onthe size of the truck, the size and type of nearby vehicles, road and/orweather conditions, etc. Another factor includes avoiding curbs or otherstatic objects along the route, such as street signs, mailboxes,bicycles, scooters or other small vehicles parked by the curb. Yetanother factor may include forcing the trailer(s) to go into a certaindirection during backup maneuvers such as when parking in a depot orloading dock. This may be done to ensure the swept volume of the vehiclestays within a permissible area of the depot, loading dock or otherarea. Additional factors may take into account the impact of maneuveroptions on the wear and tear of the vehicle, as well as loaddistribution. For instance, active adjustment of the wheels may reduceuneven wearing of the tire tread or reduce stress on the kingpin/fifthwheel coupling. And maneuvers may be chosen to reduce the likelihood ofcargo shifts or to correct for them.

Information regarding route planning and maneuver selection inaccordance with independent wheel actuation may also be shared withother vehicles, such as vehicles that are part of a fleet. One exampleof this is shown in FIGS. 11A and 11B. In particular, FIG. 11A is apictorial diagram 1100 and FIG. 11B is a functional diagram 1150 of anexample system that includes a plurality of computing devices 1102,1104, 1106, 1108 and a storage system 1110 connected via a network 116.The system also includes vehicles 1112 and 1114, which may be configuredthe same as or similarly to vehicle 100 of FIGS. 1A-B. Vehicles 1112and/or vehicles 1114 may be part of a fleet of vehicles. Although only afew vehicles and computing devices are depicted for simplicity, atypical system may include significantly more.

As shown in FIG. 11B, each of computing devices 1102, 1104, 1106 and1108 may include one or more processors, memory, data and instructions.Such processors, memories, data and instructions may be configuredsimilarly to the ones described above with regard to FIG. 2A.

The various computing devices and vehicles may communicate via one ormore networks, such as network 1116. The network 1116, and interveningnodes, may include various configurations and protocols including shortrange communication protocols such as Bluetooth™, Bluetooth LE™, theInternet, World Wide Web, intranets, virtual private networks, wide areanetworks, local networks, private networks using communication protocolsproprietary to one or more companies, Ethernet, WiFi and HTTP, andvarious combinations of the foregoing. Such communication may befacilitated by any device capable of transmitting data to and from othercomputing devices, such as modems and wireless interfaces.

In one example, computing device 1102 may include one or more servercomputing devices having a plurality of computing devices, e.g., a loadbalanced server farm, that exchange information with different nodes ofa network for the purpose of receiving, processing and transmitting thedata to and from other computing devices. For instance, computing device1102 may include one or more server computing devices that are capableof communicating with the computing devices of vehicles 1112 and/or1114, as well as computing devices 1104, 1106 and 1108 via the network1116. For example, vehicles 1112 and/or 1114 may be a part of a fleet ofvehicles that can be dispatched by a server computing device to variouslocations, and they may receive updated vehicle models to be used inmaneuver and/or route planning. In this regard, the computing device1102 may function as a dispatching server computing system which can beused to dispatch vehicles to different locations in order to pick up anddeliver cargo or pick up and drop off passengers. In addition, servercomputing device 1102 may use network 1116 to transmit and presentinformation to a user of one of the other computing devices or apassenger of a vehicle. In this regard, computing devices 1104, 1106 and1108 may be considered client computing devices.

As shown in FIG. 11A each client computing device 1104, 1106 and 1108may be a personal computing device intended for use by a respective user1118, and have all of the components normally used in connection with apersonal computing device including a one or more processors (e.g., acentral processing unit (CPU)), memory (e.g., RAM and internal harddrives) storing data and instructions, a display (e.g., a monitor havinga screen, a touch-screen, a projector, a television, or other devicesuch as a smart watch display that is operable to display information),and user input devices (e.g., a mouse, keyboard, touchscreen ormicrophone). The client computing devices may also include a camera forrecording video streams, speakers, a network interface device, and allof the components used for connecting these elements to one another.

Although the client computing devices may each comprise a full-sizedpersonal computing device, they may alternatively comprise mobilecomputing devices capable of wirelessly exchanging data with a serverover a network such as the Internet. By way of example only, clientcomputing devices 1106 and 1108 may be mobile phones or devices such asa wireless-enabled PDA, a tablet PC, a wearable computing device (e.g.,a smartwatch), or a netbook that is capable of obtaining information viathe Internet or other networks.

In some examples, client computing device 1104 may be a remoteassistance workstation used by an administrator or operator tocommunicate with passengers of dispatched vehicles. Although only asingle remote assistance workstation 1104 is shown in FIGS. 11A-11B, anynumber of such workstations may be included in a given system. Moreover,although operations workstation is depicted as a desktop-type computer,operations works stations may include various types of personalcomputing devices such as laptops, netbooks, tablet computers, etc.

Storage system 1110 can be of any type of computerized storage capableof storing information accessible by the server computing devices 1102,such as a hard-drive, memory card, ROM, RAM, DVD, CD-ROM, flash driveand/or tape drive. In addition, storage system 1110 may include adistributed storage system where data is stored on a plurality ofdifferent storage devices which may be physically located at the same ordifferent geographic locations. Storage system 1110 may be connected tothe computing devices via the network 1116 as shown in FIGS. 11A-B,and/or may be directly connected to or incorporated into any of thecomputing devices.

Storage system 1110 may store various types of information. Forinstance, in addition to vehicle models for each type of vehicle in thefleet, the storage system 1110 may also store autonomous vehicle controlsoftware which is to be used by vehicles, such as vehicles 1112 or 1114,to operate such vehicles in an autonomous driving mode. Storage system1110 may also store map information, route information, weatherinformation, etc. This information may be shared with the vehicles 1112and 1114, for instance to help with real-time route planning andmaneuver evaluation and selection by the on-board computer system(s).The remote assistance workstation 1104 may access the stored informationand use it to assist operation of a single vehicle or a fleet ofvehicles. By way of example, a lead vehicle may select a route or plan amaneuver and send information about this to the remote assistanceworkstation 1104. In turn, the remote assistance workstation 904 maydisseminate the information to other vehicles in the fleet, so that theymay adjust their route plans or select maneuvers accordingly.

In a situation where there is a passenger or remote assistance personnel(e.g., a safety driver) in the vehicle, the vehicle or remote assistanceworkstation may communicate directly or indirectly with the person'sclient computing device. Here, for example, information may be providedto the person regarding current driving operations, changes to theroute, special maneuvers, etc.

FIG. 12 illustrates an example process 1200 in accordance with the abovediscussions. In particular, the process provides a method of controllinga vehicle configured to operate in an autonomous driving mode. Thevehicle including a plurality of wheels arranged in two or more wheelsets, where each wheel set is configured for independent actuationrelative to the other wheel sets. At block 1202, a control system of thevehicle receives sensor data from a perception system of the vehicle. Atblock 1204, the control system creates a control plan based on thereceived sensor data. At block 1206, the process includes identifyingselected wheels in the two or more wheel sets to adjust based on thecontrol plan. And at block 1208, the identified wheels are actuatedindependently of one another according to the control plan whenoperating in the autonomous driving mode

Unless otherwise stated, the foregoing alternative examples are notmutually exclusive, but may be implemented in various combinations toachieve unique advantages. As these and other variations andcombinations of the features discussed above can be utilized withoutdeparting from the subject matter defined by the claims, the foregoingdescription of the embodiments should be taken by way of illustrationrather than by way of limitation of the subject matter defined by theclaims. In addition, the provision of the examples described herein, aswell as clauses phrased as “such as,” “including” and the like, shouldnot be interpreted as limiting the subject matter of the claims to thespecific examples; rather, the examples are intended to illustrate onlyone of many possible embodiments. Further, the same reference numbers indifferent drawings can identify the same or similar elements. Theprocesses or other operations may be performed in a different order orsimultaneously, unless expressly indicated otherwise herein.

1. A vehicle configured to operate in an autonomous driving mode,comprising: a driving system including a steering subsystem, anacceleration subsystem and a deceleration subsystem to control drivingof the vehicle in the autonomous driving mode; a plurality of wheelseach configured for independent actuation by the driving system relativeto the other wheels; a perception system including one or more sensorsconfigured to detect objects in an environment surrounding the vehicle,each of the one or more sensors being positioned along the vehicle; anda control system operatively connected to the driving system and theperception system, the control system having one or more computerprocessors configured to: receive sensor data from the perceptionsystem; determine a road condition based upon the received sensor data;identify selected ones of the plurality of wheels to independentlyactuate in order to address the road condition; and cause actuation ofthe selected wheels independently of one another to adjust a height ofat least a portion of the vehicle when operating in the autonomousdriving mode to address the road condition.
 2. The vehicle of claim 1,wherein the road condition includes an uneven road surface, andactuation of the selected wheels is performed to smooth out a ride ofthe vehicle over the uneven road surface.
 3. The vehicle of claim 1,wherein the road condition includes an object along or adjacent to aroadway, and actuation of the selected wheels is performed to avoid theobject.
 4. The vehicle of claim 3, wherein the object is a static objectalong or adjacent to the roadway.
 5. The vehicle of claim 4, wherein thestatic object is a curb or signage.
 6. The vehicle of claim 4, whereinthe static object is another vehicle positioned along or adjacent to theroadway.
 7. A vehicle configured to operate in an autonomous drivingmode, comprising: a driving system including a steering subsystem, anacceleration subsystem and a deceleration subsystem to control drivingof the vehicle in the autonomous driving mode; a plurality of wheelseach configured for independent actuation by the driving system relativeto the other wheels; a perception system including one or more sensorsconfigured to detect objects in an environment surrounding the vehicle,each of the one or more sensors being positioned along the vehicle; anda control system operatively connected to the driving system and theperception system, the control system having one or more computerprocessors configured to: receive sensor data from the perceptionsystem; plan a trajectory based upon the received sensor data and astored model of the vehicle; identify selected ones of the plurality ofwheels to independently actuate to achieve the planned trajectory; andcause actuation of the selected wheels independently of one another whenoperating in the autonomous driving mode to achieve the plannedtrajectory.
 8. The vehicle of claim 7, wherein the trajectory is plannedto minimize a turning radius of the vehicle when making a turn whilemaintaining a threshold distance from an object detected in the receivedsensor data.
 9. The vehicle of claim 7, wherein the trajectory isplanned to achieve an in-lane driving adjustment while maintaining athreshold distance from an object detected in the received sensor data.10. The vehicle of claim 7, wherein the trajectory is planned for thevehicle to pull out of a parking spot.
 11. The vehicle of claim 7,wherein the one or more computer processors are further configured toplan the trajectory based upon at least one of a type of nearby vehicleor a weather condition in an external environment of the vehicle. 12.The vehicle of claim 7, wherein the trajectory is planned for thevehicle to perform a reverse driving maneuver.
 13. The vehicle of claim7, wherein the trajectory is planned according to a load distribution ofthe vehicle.
 14. The vehicle of claim 7, wherein the trajectory isplanned for the vehicle to achieve a selected position relative to acurb.
 15. The vehicle of claim 7, wherein the trajectory is planned toachieve a selected positioning of the vehicle when accessing a loadingarea.
 16. The vehicle of claim 7, wherein the stored model of thevehicle is used to plan the trajectory according to a swept volume ofspace criteria.
 17. A method for operating a vehicle in an autonomousdriving mode, the method comprising: receiving, by one or moreprocessors of a vehicle control system, sensor data from a perceptionsystem of the vehicle; determining, by the one or more processors, aroad condition based upon the received sensor data; identifying, by theone or more processors, selected ones of a plurality of wheels of thevehicle to independently actuate in order to address the road condition;and actuating the selected wheels independently of one another to adjusta height of at least a portion of the vehicle when operating in theautonomous driving mode to address the road condition.
 18. The method ofclaim 17, wherein the road condition includes: an uneven road surface,and actuating the selected wheels is performed to smooth out a ride ofthe vehicle over the uneven road surface; or an object along or adjacentto a roadway, and actuating the selected wheels is performed to avoidthe object.
 19. A method for operating a vehicle in an autonomousdriving mode, the method comprising: receiving, by one or moreprocessors of a vehicle control system, sensor data from a perceptionsystem of the vehicle; planning, by the one or more processors, atrajectory based upon the received sensor data and a stored model of thevehicle; identifying, by the one or more processors, selected ones of aplurality of wheels of the vehicle to independently actuate to achievethe planned trajectory; and actuating the selected wheels independentlyof one another when operating in the autonomous driving mode to achievethe planned trajectory.
 20. The method of claim 19, wherein thetrajectory is further planned based upon at least one of a type ofnearby vehicle or a weather condition in an external environment of thevehicle.